a) Field of the Invention
The present invention relates to the use of a polyolefin resin composition comprising a random copolymer of an alkenylsilane and an .alpha.-olefin as a material for adhesion. The composition of the invention is particularly advantageous for adhering a metal and a polyolefin or adhering a polymer containing polar groups and a polyolefin.
The present invention also relates to the use of such a polyolefin resin composition material as an easy coating material.
b) Description of the Related Art
It is known to employ a multi-layer structure comprising a polyolefin layered between polymers containing polar groups, such as a saponified ethylene-vinyl acetate copolymer (such as EVAL), nylon or polyester in order to obtain the beneficial properties imparted by a polyolefin, as well as the beneficial properties imparted by polymers containing polar groups, such as gas barrier properties, which cannot be achieved through the use of a polyolefin alone.
It is also known to employ a multi-layer structure comprising a polyolefin and a metal such as iron or aluminum.
However, due to incompatibility between a polyolefin and polymers containing polar groups, and bad drapeability between a polyolefin and a metal, the materials cannot be directly adhered. Thus, when such multi-layer structures are employed, an adhesive resin is inserted between the polyolefin and the polymers containing polar groups, or between the polyolefin and the metal.
A composition comprising a graft polymer of polyolefin and anhydrous maleic acid has been used as an adhesive resin in such multi-layer structures. A polyolefin is useful in various applications including exterior paint. However, a polyolefin has poor coating properties and thus, if used alone, easily peels. Thus, a composition comprising a graft polymer of polyolefin and anhydrous maleic acid is widely employed as an adhesive resin to adhere a polyolefin to the surface of a molded component or to treat the surface of a molded component by plasma. Plasma treatment requires a complicated method and special equipment is required.
It is desirable to develop a resin composition which will improve the coating properties of a polyolefin upon being mixed therewith. A graft polymer of anhydrous maleic acid and polyolefin improves the adhesiveness between a polyolefin and a polymer containing a polar group to a certain extent. However, when the graft copolymer is used to adhere a saponified ethylene-vinyl acetate copolymer and a polyolefin or a metal, poor adhesive properties result. Further, when used to adhere a polyolefin with a metal, there is a problem of corrosion of the metal.
Thus, it has been desired to produce a resin which shows better adhesiveness.
As set forth in a co-pending application entitled .alpha.-Olefin Block Copolymers And Processes for Preparing The Same, filed in the United States Patent and Trademark Office on Nov. 16, 1988, applicants discovered that an .alpha.-olefin block copolymer comprising an alkenylsilane and an .alpha.-olefin is useful as a material for adhesion.
A random copolymer of an alkenylsilane and an .alpha.-olefin polymerized in the presence of a transition metal compound and an organic compound is disclosed in U.S. Pat. No. 3,223,686. It is also disclosed in U.S. Pat. No. 3,644,306 that such a copolymer is used to obtain a crosslinkable material. However, it has not been previously known that this copolymer is useful as a material for adhesion and for easy coating materials.